diff options
Diffstat (limited to 'man-pages-posix-2013/man3p/pthread_rwlock_timedrdlock.3p')
-rw-r--r-- | man-pages-posix-2013/man3p/pthread_rwlock_timedrdlock.3p | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/man-pages-posix-2013/man3p/pthread_rwlock_timedrdlock.3p b/man-pages-posix-2013/man3p/pthread_rwlock_timedrdlock.3p new file mode 100644 index 0000000..5ad394f --- /dev/null +++ b/man-pages-posix-2013/man3p/pthread_rwlock_timedrdlock.3p @@ -0,0 +1,148 @@ +'\" et +.TH PTHREAD_RWLOCK_TIMEDRDLOCK "3P" 2013 "IEEE/The Open Group" "POSIX Programmer's Manual" +.SH PROLOG +This manual page is part of the POSIX Programmer's Manual. +The Linux implementation of this interface may differ (consult +the corresponding Linux manual page for details of Linux behavior), +or the interface may not be implemented on Linux. + +.SH NAME +pthread_rwlock_timedrdlock +\(em lock a read-write lock for reading +.SH SYNOPSIS +.LP +.nf +#include <pthread.h> +#include <time.h> +.P +int pthread_rwlock_timedrdlock(pthread_rwlock_t *restrict \fIrwlock\fP, + const struct timespec *restrict \fIabstime\fP); +.fi +.SH DESCRIPTION +The +\fIpthread_rwlock_timedrdlock\fR() +function shall apply a read lock to the read-write lock referenced by +.IR rwlock +as in the +\fIpthread_rwlock_rdlock\fR() +function. However, if the lock cannot be acquired without waiting for +other threads to unlock the lock, this wait shall be terminated when +the specified timeout expires. The timeout shall expire when the +absolute time specified by +.IR abstime +passes, as measured by the clock on which timeouts are based (that is, +when the value of that clock equals or exceeds +.IR abstime ), +or if the absolute time specified by +.IR abstime +has already been passed at the time of the call. +.P +The timeout shall be based on the CLOCK_REALTIME clock. +The resolution of the timeout shall be the resolution of the +CLOCK_REALTIME clock. The +.BR timespec +data type is defined in the +.IR <time.h> +header. Under no circumstances shall the function fail with a timeout +if the lock can be acquired immediately. The validity of the +.IR abstime +parameter need not be checked if the lock can be immediately acquired. +.P +If a signal that causes a signal handler to be executed is delivered to +a thread blocked on a read-write lock via a call to +\fIpthread_rwlock_timedrdlock\fR(), +upon return from the signal handler the thread shall resume waiting for +the lock as if it was not interrupted. +.P +The calling thread may deadlock if at the time the call is made it +holds a write lock on +.IR rwlock . +The results are undefined if this function is called with an +uninitialized read-write lock. +.SH "RETURN VALUE" +The +\fIpthread_rwlock_timedrdlock\fR() +function shall return zero if the lock for reading on the read-write +lock object referenced by +.IR rwlock +is acquired. Otherwise, an error number shall be returned to indicate +the error. +.SH ERRORS +The +\fIpthread_rwlock_timedrdlock\fR() +function shall fail if: +.TP +.BR ETIMEDOUT +The lock could not be acquired before the specified timeout expired. +.P +The +\fIpthread_rwlock_timedrdlock\fR() +function may fail if: +.TP +.BR EAGAIN +The read lock could not be acquired because the maximum number of read +locks for lock would be exceeded. +.TP +.BR EDEADLK +A deadlock condition was detected or the calling thread already holds a +write lock on +.IR rwlock . +.TP +.BR EINVAL +The +.IR abstime +nanosecond value is less than zero or greater than or equal to 1\|000 +million. +.P +This function shall not return an error code of +.BR [EINTR] . +.LP +.IR "The following sections are informative." +.SH EXAMPLES +None. +.SH "APPLICATION USAGE" +Applications using this function may be subject to priority inversion, +as discussed in the Base Definitions volume of POSIX.1\(hy2008, +.IR "Section 3.287" ", " "Priority Inversion". +.SH RATIONALE +If an implementation detects that the value specified by the +.IR rwlock +argument to +\fIpthread_rwlock_timedrdlock\fR() +does not refer to an initialized read-write lock object, it is +recommended that the function should fail and report an +.BR [EINVAL] +error. +.SH "FUTURE DIRECTIONS" +None. +.SH "SEE ALSO" +.ad l +.IR "\fIpthread_rwlock_destroy\fR\^(\|)", +.IR "\fIpthread_rwlock_rdlock\fR\^(\|)", +.IR "\fIpthread_rwlock_timedwrlock\fR\^(\|)", +.IR "\fIpthread_rwlock_trywrlock\fR\^(\|)", +.IR "\fIpthread_rwlock_unlock\fR\^(\|)" +.ad b +.P +The Base Definitions volume of POSIX.1\(hy2008, +.IR "Section 3.287" ", " "Priority Inversion", +.IR "Section 4.11" ", " "Memory Synchronization", +.IR "\fB<pthread.h>\fP", +.IR "\fB<time.h>\fP" +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 7, Copyright (C) 2013 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. +(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the +event of any discrepancy between this version and the original IEEE and +The Open Group Standard, the original IEEE and The Open Group Standard +is the referee document. The original Standard can be obtained online at +http://www.unix.org/online.html . + +Any typographical or formatting errors that appear +in this page are most likely +to have been introduced during the conversion of the source files to +man page format. To report such errors, see +https://www.kernel.org/doc/man-pages/reporting_bugs.html . |